284 VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 



SUMMARY. 



i. The lytic principles of venom for blood corpuscles are active over a 

 wider group of animals than the agglutinative principles. 



2. The more distant, as a rule, the animal groups are from the vertebrates 

 the less the susceptibility of their blood corpuscles to venom lysins and agglu- 

 tinins. 



3. In one instance only — that of Sphenoides maculatus — did the blood 

 corpuscles prove wholly insusceptible to the action of venom. This animal 

 is, however, susceptible to the toxic action of venom, although crotalus venom 

 produces death without causing haemorrhage. According, therefore, to the 

 view of the constitution of venom held by Professor Flexner and myself, 

 this animal is subject chiefly to the action of the neurotoxic constituent of 

 venom. 



4. Cobra venom contains the largest and crotalus venom the smallest num- 

 ber of haemolytic units, while moccasin venom contains the largest number 

 of agglutinative units for these bloods. 



5. The mechanism of venom lysis in these animals is identical with that 

 in warm-blooded animals. Complements are therefore present in all verte- 

 brates and many, at least, invertebrate species. 



6. The heat liability of the venom agglutinins and hemolysins for cold- 

 blooded animals agrees closely with that for warm-blooded animals. 



EFFECTS OF SNAKE VENOMS ON THE NERVE TISSUES, OVA, AND 



SPERMATOZOA. 



The marked cytolytic properties of various snake venoms upon the nerve 

 tissues, ova, and spermatozoa have already been described in detail under 

 the heading cytolysins in snake venom and neurolysis in vitro, and I shall not 

 repeat at this place. It suffices to say that the individual groups of these cells 

 are affected by various venoms in various manners, depending upon the 

 source of the materials. 



